How to anchor posts to concrete floor?

I'm installing some closet doors along a bedroom wall. I faced with a dilemma if anchoring posts to the floor (which is concrete slab). These posts need to be solid because my doors will be attached to them.

 

You say "posts". You should be anchoring a sill plate to the cement. Your header fits between the king studs... your trimmer studs are under the header... the king and trimmers studs (not a post) get toenailed to the sill plate.

I dont know why people think a 4x4 post is the thing to use around a doorway. They are far more likely to warp.

 

Is a "sill plate" some sort of metal piece? Have a Home Depot link? Maybe I need some sort of corner brace like this? http://www.homedepot.com/catalog/pro...d35c8_1000.jpg
I have yet to pull up the carpet. Not sure how the existing post (or wood or whatever you want to call it) is anchored.
I need to tighten up the space between left and right in order to hang the doors in snug. Space is 52 5/8. 24' doors is the only thing they make now before jumping up to 28' or 30".

 

Basically you would build the structure with a 2x4 (or 2x6 depending on the existing wall structure) horizontal on the ground and nailed into the concrete. You would then use 2x4 structures to build the frame. It would look essentially like this [ATTACH=CONFIG]77249[/ATTACH]

 

Two 24" doors plus
a doorjamb is approximately 24" + 24" + 5/8" + 5/8" = 49¼". It is a good idea to allow a ½" on each side for shimming the door jamb so that makes a total of about 50¼" so you are only left with about 2" to fill. A 1x4 plus a half inch plywood spacers nailed to the existing stud on each side should give you the correct opening size for your jamb. No need for a sill plate because the existing studs should already be securely fastened. I am also assuming double doors because you said doors wider than 24" are too wide.

This is based on the sumption there is an already existing opening with a header. I'm basing the assumption on your saying there is a 52 and 5/8" space which I took to mean opening from a previous door.

Edit you don't need the center stud in the above diagram because the two doors can engage each other. One door would engage the top of the doorjamb to hold both in place.

 

Yes I ripped out 3 double doors (6 in total) from the 50's or some ancient era. I ripped up carpeting around one of wood posts (see picture). I can't figure out how this post was anchored to the concrete. Glue? I see nothing around it. Just carpet tack strips. I'm worried that once I start hammering against these posts, they will start to move. Perhaps I can lay down some plywood inside the closet and have it raised. The plywood could provide support for the wooden door posts.

 

You're saying that image is of something pre existing? Totally weird. I thought it was something you were trying to add. Please step back and give us a picture of the whole wall floor to ceiling. Is this a house built on a slab or is this in a basement? If basement is that a support column in the basement?

 

Yes. Existing. I ripped out existing doors from an existing closet in the master bedroom. For what it's worth, the entire 1-story house is on a slab foundation. I'm simply asking if anyone has any ideas as to what is keeping the existing posts in place besides connections above. Glue? And what might I use to strengthen these posts at the bottom?

 

The posts are most likely just sitting on the concrete with the lateral support keeping them in place. What is your ultimate goal? Do you plan on enclosing this closet and having only one door? If so, just frame it in using a bottom plate across the two open spans held in place with powder actuated pins. Determine the door opening and install bottom plate pieces to accommodate the new jack/king studs. Don't move the two posts, just frame around them. Once the walls are in place you can remove the lateral supports to the posts.

 

I'm putting in 6 doors -- not 1 door.

 

Is this a free standing unit? What are those cables for? I agree with Ray, since it is not load bearing, put in a top plate, appropriate bottom plates, jack studs, king studs and headers with cripples. That way you can customize it for your sized doors.